package com.study.spring.utils;

import java.sql.Connection;
import java.sql.SQLException;

/**
 * @author 应癫
 */
public class ConnectionUtils {

    /**
     * 存储当前线程的连接
     */
    private final static ThreadLocal<Connection> THREAD_LOCAL = new ThreadLocal<>();

    /**
     * 从当前线程获取连接
     */
    public static Connection getCurrentThreadConn() throws SQLException {
        // 判断当前线程中是否已经绑定连接，如果没有绑定，需要从连接池获取一个连接绑定到当前线程
        Connection connection = THREAD_LOCAL.get();
        if (connection == null) {
            // 从连接池拿连接并绑定到线程
            connection = DruidUtils.getInstance().getConnection();
            // 绑定到当前线程
            THREAD_LOCAL.set(connection);
        }
        return connection;
    }
}
